Hi Rob, >> "print(require('mobdebug')._VERSION, debug.gethook())" before the line > 0.606 function() --[[..skipped..]] end "crl" 0 Just to makes sure we are on the same page with this: the line printed is from print() statement on the line that is *after* the line you do "done" command on and *before* the line with a breakpoint? The reason I want to confirm this is that debug hook should be reset when "done" is executed, so you should get "nil" instead of "function". So, let say you have: 1: require('mobdebug').start() 2: something else 3: print(require('mobdebug')._VERSION, debug.gethook()) 4: line with a breakpoint You start debugging and the application is suspended with the current line marker is on line 2. You click on "Project | Detach Process". The application continues, prints the line you included above, and throws the error on line 4. Correct? Using these steps I can't reproduce the issue with 0.606. Is this code inside a coroutine by any chance? Are you using Lua 5.1, 5.2, or LuaJIT? > Ah ... that's interesting. I DO have breakpoints after clicking on that. Is > that the answer? It's sort of sensible it would throw an error... Yes, the issue only happens when you have a breakpoint later in the code, but it still shouldn't throw the error (and this is what is supposed to be fixed in 0.606). Paul.